Preheat oven to 180° C. Line a 16 cm springform cake tin with baking paper.
Mix 10g of ground chia seeds with 50 ml of water. Stir and let it rest for 2-3 minutes to thicken.
In a large bowl, mix together the dry ingredients: white rice flour, finely ground almonds, finely ground rolled oats, brown rice flour, coconut sugar, cacao powder, baking powder, and a pinch of baking soda.
Blend banana with 180 ml of rice milk. Add the banana and the chia seed mixture to the bowl with dry ingredients. Also, add 60 ml melted coconut oil. Mix with a hand mixer until all is well combined. Note: If the batter is too thick, you can add an extra 1 to 2 tablespoons of rice milk.
Pour the batter into the prepared cake tin and smooth the top with a rubber spatula. Bake for approx. 40-45 minutes.
Remove from the oven and let it cool down.
Melt chocolate in a medium pot over low heat. Stir until smooth.
Add coconut cream, melted chocolate, and agave or maple syrup to the blender and blend until smooth and silky.
Spread the frosting evenly all over the cake.
Top with blueberries.
Always chill your coconut milk in the refrigerator overnight, being sure not to shake or tip the can to encourage separation of the cream and liquid.